The present invention relates to sprinkler units, and pertains particularly to a rotary stream sprinkler unit.
In U.S. Pat. No. 3,854,664, issued Dec. 17, 1974, to Edwin J. Hunter, and entitled "SPRINKLER SYSTEMS", there is disclosed a sprinkler unit which has a rotating head that directs a plurality of rotating streams over an area to be watered. In that prior device, the streams of water are formed in nozzles in the rotating head. The rotating head has inlets to the nozzle on one end, which engages and cooperates with an orifice plate for acting as a valve for controlling communication of pressurized water to the nozzles.
U.S. Pat. No. 4,471,908, issued Sept. 18, 1984, to Edwin J. Hunter, and entitled "PATTERN SPRINKLER HEAD" discloses a similar sprinkler unit having V-shaped nozzles in a cylindrical rotating head. The nozzle inlet openings cooperate with an orifice in an orifice plate providing a valve action to vary the nozzle openings to the source of pressurized water. This combination delivers streams of water of variable length and volume from the nozzles in the distributor head. The orifice opening in the plate defines the spray pattern to be produced by the streams issuing from the nozzles in the rotating head.
Among the problems of the prior device is that sand and grit from the water supply gets on the orifice plate and rapidly wears the plate and seals of the unit. In some instances, the sand and grit can cause the unit to stall. These and other problems of the prior device have prevented it from being satisfactory.
In co-pending application Ser. No. 878,591, filed June 26, 1986, of Edwin J. Hunter, entitled "ROTARY STREAM SPRINKLER UNIT", there is disclosed a sprinkler unit, that is an improvement of the aforementioned patents, that utilizes an axially spaced open channel head for forming and directing the streams. It also utilizes specially configured passages or nozzles to form and control each of the streams to the channels in the head. It has been found that the passages are subject to plugging due to particles of sand, flakes and the like in the water.
In a second co-pending application Ser. No. 121,400, filed Nov. 6, 1987, entitled "ROTARY STREAM SPRINKLER UNIT", of Edwin J. Hunter, there is disclosed a sprinkler unit, that is an improvement of that disclosed in the aforementioned co-pending application, both of which are allowed and are incorporated herein by reference as though fully set forth. The second of the aforementioned applications discloses a sprinkler unit that utilizes an axially spaced open channel head and specially configured arcuate passages or nozzles to form and control each of the streams to the channels in the head for controlling area and amount of coverage. This embodiment also reduces some of the clogging problems associated with some of the other embodiments. However, it has been found that thirty-six different nozzle inserts are required to provide the consumer with his normal requirements as to arc and area of coverage. We have devised modifications that enable this requirement to be met with four different inserts.
Accordingly, it is desirable that an improved rotary stream sprinkler unit be available.